#include<bits/stdc++.h>
using namespace std;
typedef pair<int,int>P;
typedef vector<int>VI;
#define rep(i,n) for(int i=0;i<(n);i++)
#define pb push_back
#define all(v) (v).begin(),(v).end()
#define maxv(a,b) (a)=max((a),(b))
#define minv(a,b) (a)=min((a),(b))
const int INF=114514;
int N,M;
int A[10],B[10];

int dp[1<<11];

int main(){
    cin>>N;rep(i,N)cin>>A[i];
    cin>>M;rep(i,M)cin>>B[i];
    sort(B,B+M);reverse(B,B+M);

    rep(i,1<<N)dp[i]=INF;
    dp[0]=0;

    rep(i,1<<N){
        if(dp[i]>=M)continue;
        rep(j,1<<N){
            if(i&j)continue;
            int sum=0;
            rep(k,N)if(j>>k&1)sum+=A[k];
            if(sum>B[dp[i]])continue;
            minv(dp[i|j],dp[i]+1);
        }
    }

    if(dp[(1<<N)-1]==INF)cout<<-1<<endl;
    else cout<<dp[(1<<N)-1]<<endl;
    return 0;
}